A hole as large as Lake Superior or the state of Maine has opened up in Antarctica, and scientists aren’t sure why it’s there.
The gigantic, mysterious hole “is quite remarkable,” atmospheric physicist Kent Moore, a professor at the University of Toronto’s Mississauga campus, told Motherboard over the phone.
Areas of open water surrounded by sea ice, such as this one, are known as polynias. They form in coastal regions of Antarctica.
What’s strange here, though, is that this polynia is “deep in the ice pack.”
This is hundreds of kilometres from the ice edge. If we didn’t have a satellite, we wouldn’t know it was there.”)
A polynia was observed in the same location, in Antarctica’s Weddell Sea, in the 1970s. Back then, scientists’ observation tools weren’t nearly as good, so that hole remained largely unstudied. Then it went away for four decades, until last year, when it reopened for a few weeks. Now it’s back again.
“This is now the second year in a row it’s opened after 40 years of not being there,” Moore said. (It opened around September 9.) “We’re still trying to figure out what’s going on.”
Scientists can say with certainty that the polynia will have a wider impact on the oceans. “Once the sea ice melts back, you have this huge temperature contrast between the ocean and the atmosphere,” Moore explained. “It can start driving convection.” Denser, colder water sinks to the bottom of the ocean, while warmer water comes to the surface, “which can keep the polynia open once it starts,” he said.
Antarctica is undergoing massive changes right now, and figuring out why a gaping hole could suddenly open up will be key to understanding larger systems at play.